A multimillion-dollar industry has emerged around caring for them, with many veterinarians specializing in exotic pet care and herpetology. In addition to the internet, reptiles are sold at pet stores, flea markets, street vendors and herpetology fairs.

Reptiles are popular pets because they are relatively quiet, odorless and “compatible with modern lifestyles,” said Gordon Burghardt, a herpetologist who specializes in behavior at the University of Tennessee, Knoxville. (As a child in the 1950s, he got his start with dime-store turtles and lizards.)